The correct answer is 2) Spread anti-slavery sentiment in the North.
Uncle Tom's Cabin was a famous book written by Harriet Beecher Stowe right before the outbreak of the American Civil War. This book, despite being fictional, was a story that contained elements of truth within regarding slavery in American southeast. The violence and brutality associated with this institution that was described in this book resulted in an increase in sentiment against this institution in the states where slavery was already outlawed.